<template>
	<view class="uni-numbox">
		<view @click="_calcValue('minus')" class="uni-numbox__minus uni-numbox-btns" :style="{background}">
			<text class="uni-numbox--text" :class="{ 'uni-numbox--disabled': inputValue <= min || disabled }" :style="{color}">-</text>
		</view>
		<input :disabled="disabled" @focus="_onFocus" @blur="_onBlur" class="uni-numbox__value" type="number"
			v-model="inputValue" :style="{background, color}" />
		<view @click="_calcValue('plus')" class="uni-numbox__plus uni-numbox-btns" :style="{background}">
			<text class="uni-numbox--text" :class="{ 'uni-numbox--disabled': inputValue >= max || disabled }" :style="{color}">+</text>
		</view>
	</view>
</template>
<script>
/**
	 * NumberBox 数字输入框
	 * @description 带加减按钮的数字输入框
	 * @tutorial https://ext.dcloud.net.cn/plugin?id=31
	 * @property {Number} value 输入框当前值
	 * @property {Number} min 最小值
	 * @property {Number} max 最大值
	 * @property {Number} step 每次点击改变的间隔大小
	 * @property {String} background 背景色
	 * @property {String} color 字体颜色（前景色）
	 * @property {Boolean} disabled = [true|false] 是否为禁用状态
	 * @event {Function} change 输入框值改变时触发的事件，参数为输入框当前的 value
	 * @event {Function} focus 输入框聚焦时触发的事件，参数为 event 对象
	 * @event {Function} blur 输入框失焦时触发的事件，参数为 event 对象
	 */

export default {
  name: 'UniNumberBox',
  emits: ['change', 'input', 'update:modelValue', 'blur', 'focus'],
  props: {
    value: {
      type: [Number, String],
      default: 1
    },
    modelValue: {
      type: [Number, String],
      default: 1
    },
    min: {
      type: Number,
      default: 0
    },
    max: {
      type: Number,
      default: 100
    },
    step: {
      type: Number,
      default: 1
    },
    background: {
      type: String,
      default: '#f5f5f5'
    },
    color: {
      type: String,
      default: '#333'
    },
    disabled: {
      type: Boolean,
      default: false
    }
  },
  data () {
    return {
      inputValue: 0
    }
  },
  watch: {
    value (val) {
      this.inputValue = +val
    },
    modelValue (val) {
      this.inputValue = +val
    }
  },
  created () {
    if (this.value === 1) {
      this.inputValue = +this.modelValue
    }
    if (this.modelValue === 1) {
      this.inputValue = +this.value
    }
  },
  methods: {
    _calcValue (type) {
      if (this.disabled) {
        return
      }
      const scale = this._getDecimalScale()
      let value = this.inputValue * scale
      const step = this.step * scale
      if (type === 'minus') {
        value -= step
        if (value < (this.min * scale)) {
          return
        }
        if (value > (this.max * scale)) {
          value = this.max * scale
        }
      }

      if (type === 'plus') {
        value += step
        if (value > (this.max * scale)) {
          return
        }
        if (value < (this.min * scale)) {
          value = this.min * scale
        }
      }

      this.inputValue = (value / scale).toFixed(String(scale).length - 1)
      this.$emit('change', +this.inputValue)
      // TODO vue2 兼容
      this.$emit('input', +this.inputValue)
      // TODO vue3 兼容
      this.$emit('update:modelValue', +this.inputValue)
    },
    _getDecimalScale () {
      let scale = 1
      // 浮点型
      if (~~this.step !== this.step) {
        scale = Math.pow(10, String(this.step).split('.')[1].length)
      }
      return scale
    },
    _onBlur (event) {
      this.$emit('blur', event)
      let value = event.detail.value
      if (!value) {
        // this.inputValue = 0;
        return
      }
      value = +value
      if (value > this.max) {
        value = this.max
      } else if (value < this.min) {
        value = this.min
      }
      const scale = this._getDecimalScale()
      this.inputValue = value.toFixed(String(scale).length - 1)
      this.$emit('change', +this.inputValue)
      this.$emit('input', +this.inputValue)
    },
    _onFocus (event) {
      this.$emit('focus', event)
    }
  }
}
</script>
<style lang="scss" scoped>
	$box-height: 26px;
	$bg: #f5f5f5;
	$br: 2px;
	$color: #333;

	.uni-numbox {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		flex-direction: row;
	}

	.uni-numbox-btns {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		flex-direction: row;
		align-items: center;
		justify-content: center;
		padding: 0 8px;
		background-color: $bg;
		/* #ifdef H5 */
		cursor: pointer;
		/* #endif */
	}

	.uni-numbox__value {
		margin: 0 2px;
		background-color: $bg;
		width: 40px;
		height: $box-height;
		text-align: center;
		font-size: 14px;
		border-left-width: 0;
		border-right-width: 0;
		color: $color;
	}

	.uni-numbox__minus {
		border-top-left-radius: $br;
		border-bottom-left-radius: $br;
	}

	.uni-numbox__plus {
		border-top-right-radius: $br;
		border-bottom-right-radius: $br;
	}

	.uni-numbox--text {
		// fix nvue
		line-height: 20px;

		font-size: 20px;
		font-weight: 300;
		color: $color;
	}

	.uni-numbox .uni-numbox--disabled {
		color: #c0c0c0 !important;
		/* #ifdef H5 */
		cursor: not-allowed;
		/* #endif */
	}
</style>
